THE SIZE EVOLUTION OF PASSIVE GALAXIES: OBSERVATIONS FROM THE WIDE-FIELD CAMERA 3 EARLY RELEASE SCIENCE PROGRAM

Journal Article · Tue Apr 10 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/749/1/53· OSTI ID:22020463

Ryan, Jr, R E ^[1]; McCarthy, P J ^[2]; Cohen, S H; Rutkowski, M J; Mechtley, M R; Windhorst, R A ^[3]; Yan, H ^[4]; Hathi, N P ^[5]; Koekemoer, A M; Bond, H E; Bushouse, H ^[6]; O'Connell, R W ^[7]; Balick, B ^[8]; Calzetti, D ^[9]; Crockett, R M ^[10]; Disney, M ^[11]; Dopita, M A ^[12]; Frogel, J A ^[13]; Hall, D N. B. ^[14]; others, and

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1. Physics Department, University of California, Davis, CA 95616 (United States)
2. Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States)
3. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)
4. Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States)
5. Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States)
6. Space Telescope Science Institute, Baltimore, MD 21218 (United States)
7. Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)
8. Department of Astronomy, University of Washington, Seattle, WA 98195 (United States)
9. Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)
10. Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom)
11. School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom)
12. Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia)
13. Galaxies Unlimited, Lutherville, MD 21093 (United States)
14. Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)

We present the size evolution of passively evolving galaxies at z {approx} 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z {approx}> 1.5. We identify 30 galaxies in {approx}40 arcmin{sup 2} to H < 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 {mu}m {approx}< {lambda}{sub obs} {approx}< 1.6 {mu}m with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of {approx}0.033(1 + z). We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M{sub *} {approx} 10{sup 11} M{sub Sun }) undergo the strongest evolution from z {approx} 2 to the present. Parameterizing the size evolution as (1 + z){sup -{alpha}}, we find a tentative scaling of {alpha} Almost-Equal-To (- 0.6 {+-} 0.7) + (0.9 {+-} 0.4)log (M{sub *}/10{sup 9} M{sub Sun }), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of high-redshift systems. We discuss the implications of this result for the redshift evolution of the M{sub *}-R{sub e} relation for red galaxies.

• OSTI ID: 22020463
• Journal Information: Astrophysical Journal, Vol. 749, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CAMERAS
GALACTIC EVOLUTION
GALAXIES
MASS
PHOTOMETRY
RED SHIFT
STARS
TELESCOPES